Hydraulic transmission



Jan. 14, 1941. c, v, w T ms 2,228,799

HYDRAULIC TRANSMISSION Filed Nov. 15, 1939 3 Sheets-Sheet l I f; Z .24 j

m fi L5 /6 if y Inventor flzmfi'zbwv Jun, 1941. c. v. WATKINS 2,228,799

amawmc 'musmssron Filed Nov. 15, 192 Shots-Sheet z Inventor A itomeys 1941? c. v. WATKINS HYDRAULIC TRANSMISSION I Filed Nov. 15, v19:9

3 Shuts-Sheet 3 Inventor Attorneys Patented Jan. 14, 1941 2 22 799 UNITED STATES PATENT oFFicE HYDRAULIC TRANSMISSION Carl V. Watkins, Sultan, Wash.

Application November 15, 1939, Serial No. 304,628

2 Claims. (Cl. 192-60) The present invention relates to new and useful reciprocation in guideways II which are provided improvements in hydraulic transmissions particutherefor in the housing I. The reference numeral larly for automobiles and has for its primary 010- I2 designates pistons which are operable in the ject to provide, in a manner as hereinafter set cylinders 4 and which are connected to the fol- 5 forth, a device of this character embodying means lowers ID by rods [3. Thus, the pistons I2 are 5 whereby any desired power or speed ratio between connected to the shaft I for actuation thereby. the engine and the rear wheels of the vehicle may It' may be well to here state that the cylinders 4 be had. are for the reception of a suitable fluid and it will Another very important object of the invention be observed that the construction and arrangeis to provide, in a hydraulic transmission of the ment is such that this fluid will be caused to flow 10 valve controlled type, novel means for actuating back and forth between the pairs of cylinders the valves. through the passages 5 when the shaft I is rotat- Other objects of the invention are to provide a ing and the valves 6 are open or partially open.

hydraulic transmission of the character described Bearings I4 are provided in the end members 3 which will be comparatively simple in construcand 4' for the shaft l. 15

tion, strong, durable, highly efficient and reliable Extending rearwardly from the member 3' of in use, compact, light in weight and which may be the housing I is a driven shaft I 5. Projecting formanufactured at low cost. wardly from the member 3 of the housing I is a All of the foregoing and still further objects hub I6. The housing I is rotatably mounted inand advantages of the invention will become apsupports I'l, bearings l8 being provided for said 20 parent fromastudy of the following specification, housing. It will be noted that the hub I6 is taken in connection with the accompanying drawjournaled in one of the bearings I8 and that the ings wherein like characters of reference designate shaft I5 is journaled in the other of said bearings. corresponding parts throughout the several views, Mounted on the shaft I5 is a fluid reservoir I9. and wherein: The reservoir I9 communicates with the cylinders 5 Figure 1 is a view in side elevation of a hydraulic 4 for replenishing the fluid therein through pastransmission constructed in accordance with the sages 20 in the shaft l5 and the housing I. Air present invention, portions thereof being shown in under pressure is to be injected in the reservoir l9 vertical section. in any suitable manner for forcing the fluid there- Figure Zisaview in vertical longitudinal section from to the cylind rs 4. S t e ck v v 30 through the transmission 2| are provided for preventing the return of the Figure 3 is a cross sectional view. fluid to the reservoir I9. Figure 4 is a view in vertical section through Projecting from one end of the valves 6 are one of the control valves, taken substantially on stems 22 (see Fig. 4) having mountedthereon the line 44 of Figure 2. crossheads 23. Mounted on the housing I, ad- 35 Figure 5 is a cross sectional view, taken subjacent the crossheads 23, are cylinders 24 and stantially on the line 55 of Fig. 1. cups 25. The cups 25 accommodate coil springs Referring now to the drawings in detail, it will 26 which are operatively connected to one end of be seen that the embodiment of the invention the crossheads 23 for opening the control valves which has been illustrated comprises a housing of 6. Fluid actuated p sto s a e p ab e in th 4 suitable metal which is designated generally by cylinders'24 and connected to the other ends of the reference numeral I. The housing I includes t CrOSSheadS 23 Closing the Valves parts or sections 2, 3 and 4'. Formed in the The hub I6 of the housing I has formed therein housing I are diametrically opposite pairs of radial cylinders 28 which communicate with the cylinders cylinders 4. The pairs of cylinders 4 communicate 24 t O passages 29 in Said housing- The y 45 with each other through passages 5 which are conin s 8 are p d to r iv fluid f om a trolled by rotary valves 6, reservoir 30 on the hub I6. Pistons 3| are oper- Extending rotatably into the housing I through able in the cylinders 28 for forcing the fluid the front thereof is a drive shaft 1 which is contherefrom through the passages 29 into the cylnected directly to the engine (not shown) of the inders 24 for actuating the pistons 21. The pis- 5o vehicle. Formed on the shaft I and operable in tons 3| are connected to a ring 32 which is rothe housing I are eccentrics 8. Journaled on the tatably and slidably mounted on the shaft 1. The eccentrics 8 are substantially square bearings 9 ring 32 may be shifted longitudinally on the shaft which are mounted for reciprocation in followers 1 by a lever (not shown) or any other suitable I0. The followers II), in turn, are mounted for means.

It is thought that the operation of the transmission will be readily apparent from a consideration of the foregoing. Briefly, with the valves 6 in open position, as seen in Fig. 2 of the drawings, the shaft 1 is free to rotate independently of the housing I, the pistons l2 reciprocating freely in the cylinders 4 and forcing the fluid back and ,forth therebetween through said valves. To connect the housing I and the shaft I5 to the shaft 1 for actuation thereby, the valves 6 are rotated toward closed position. Of course, as the valves 6 are moved toward closed position the passage of the fluid therethrough is restricted and the shaft l5 begins to turn. The speed ratio of the shaft IE to the shaft 1 is controlled by the position of the valves 6. When the valves 6 are fully closed the housing I and the shaft l5 rotate in unison with the shaft 1. To close the'valves 6 the pistons are moved rearwardly in the cylinders 28. This forces the fluid from the cylinders 28 through the passages 29 into the cylinders 24 for actuating the pistons 27 thus rotating the valves 6 toward closed position against the tension of the coil springs 26. As hereinbefore stated, the fluid in the cylinders 41 may be replenished when necessary by injecting air under pressure into the reservoir 19 for forcing the fluid therefrom through the passages 2% past the check valves 2i into said cylinders.

t is believed that the many advantages of a hydraulic transmission constructed in accordance with the present invention will be readily understood and although a preferred embodiment of the device is as illustrated and described, it is to be understood that changes in the details of construction and in the combination and arrangement of parts may be resorted to which will fall within the scope of the invention as claimed.

What is claimed is:

l. A hydraulic transmission comprising a rctatably mounted housing, a driven shaft fixed to said housing for rotation therewith, a drive shaft extending rotatably into the housing, eccentrics on said drive shaft operable in the housing, pairs of communicating cylinders in the housing, said cylinders for the reception of a fluid, valves controlling the passages between the cylinders, followers mounted for reciprocation in the housing, pistons connected to said followers for actuation thereby and operable in the cylinders, bearings journaled on the eccentrics and operable in the followers for actuating same, and means for actuating the valves, the valve actuating means including coil springs mounted on the housing and operatively connected to the valves for actuating said valves to open position, fluid actuated pistons mounted on the housing and operatively connected to the valves for closing said valves, and fluid pressure means operatively connected to the last named pistons. for actuating same.

2. A hydraulic transmission of the class described comprising a rotary housing, a driven shaft fixed to said housing for rotation therewith, a drive shaft extending rotatably into the housing, pairs of communicating cylinders in the housing, rotary valves controlling the communication between the pairs of cylinders, pistons operable in the cylinders, means operatively connecting said pistons to the drive shaft for actuation thereby, additional cylinders mounted on the housing, pistons operable in the second named cylinders and operatively connected to the valves for closing said valves, a hub projecting from one end of the housing and encircling the drive shaft, cylinders in said hub and adapted to receive a fluid, the housing having passages therein connecting the second named cylinders with the third named cylinders, and pistons operable in'the third named cylinders for forcing the fluid therefrom through the passages into the second named cylinders for actuating the second named pistons for rotating the valves toward closed position, the first named cylinders being adapted to receive a fluid.

CARL V. WATKINS. 

